Contrast-Enhanced Ultrasound after Endovascular Aortic Repair: Supplement and Potential Substitute for CT in Early- and Long-Term Follow-Up.

BACKGROUND: Endoleaks are the most common complication after endovascular aneurysm repair (EVAR). Computed tomography angiography (CTA) is presently the golden standard for lifelong surveillance after EVAR. Several studies and meta-analyses have shown contrast-enhanced ultrasound (CEUS) to be a good alternative. The main goal of our study was to further validate the inclusion of CEUS in follow-up examination protocols for the systematic surveillance after EVAR. METHODS: A retrospective analysis of patients who had received CEUS as part of their routine surveillance after EVAR at our center was conducted. Detection rate and classification of endoleak types were compared between available postinterventional CTA/magnetic resonance angiography and follow-up CEUS examinations. Last preinterventional CTAs before EVAR served as baselines with focus on potential cofactors such as age, body mass index, maximum aortic aneurysm diameters, endoleak orientation, and distance-to-surface influencing detection rates and classification. RESULTS: In total, 101 patients were included in the analysis. Forty-four endoleaks (43.5% of cases) were detected by either initial CEUS or CTA, mostly type II (37.6% of the included patients). Initial CEUS showed an endoleak sensitivity of 91.2%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 84.6%. No covariate with an influence on the correct classification could be identified either for CEUS or CT. CONCLUSIONS: CEUS should be considered a valid complementary method to CTA in the lifelong surveillance after EVAR. As type II endoleaks seem to be a common early-term, sometimes spontaneously resolving complication that can potentially be missed by CTA, we suggest combined follow-up protocols including CEUS in the early on postinterventional assessment.

Imaging of Anatomical Variants of the Lower Limb Nerves: Clinical and Preoperative Relevance.

Anatomical variants of peripheral nerves of the lower limb are relatively frequent and vulnerable to injury if not considered by the surgeon. Surgical procedures or percutaneous injections are often performed without knowing the anatomical situation. In a patient with normal anatomy, these procedures are mostly performed smoothly without major nerve complications. But in the case of anatomical variants, surgery may be challenging as "new" anatomical prerequisites complicate the procedure. In this context, high-resolution ultrasonography as the first-line imaging modality to depict peripheral nerves, has become a helpful adjunct in the preoperative setting. It is crucial, on the one hand, to gain knowledge of anatomical nerve variants and, on the other hand, to depict the anatomical situation preoperatively, to minimize the risk of surgical trauma to a nerve and make surgeries safer.

Operative versus conservative treatment of acute Achilles tendon ruptures: preliminary results of clinical outcome, kinematic MRI and contrast-enhanced ultrasound.

INTRODUCTION: There is no uniform consensus on the gold standard therapy for acute Achilles tendon rupture. The aim of this pilot study was to compare operative and conservative treatment regarding imaging findings and clinical outcome. MATERIALS AND METHODS: Surgically or conservatively treated patients with acute Achilles tendon rupture were retrospectively evaluated. Differences in tendon length and diameter with and without load were analysed using kinematic MRI, tendon perfusion, structural alterations, movement and scar tissue by means of grey-scale and contrast-enhanced ultrasound (CEUS). Intra- and interobserver agreement were recorded. RESULTS: No significant difference was detected regarding clinical outcome, B mode ultrasonography, contrast-enhanced sonography or MRI findings, although alterations in MRI-based measurements of tendon elasticity were found for both groups. Considerable elongation and thickening of the injured tendon were detected in both groups. CONCLUSION: Both, conservative and surgical treatment showed comparable outcomes in our preliminary results and may suggest non-inferiority of a conservative approach.

Ultrasound of Small Nerves.

Nerve ultrasound has become an integral part of the diagnostic workup of peripheral neuropathies. Especially in the examination of small nerves, ultrasound provides superior image quality by using high frequency transducers. For a selection of small nerves, this article summarizes the local anatomy and common pathologies and offers simple instructions for determining their location with ultrasound including some cases with pathologies. This selection of nerves comprises the great auricular nerve, the supraclavicular nerves, the suprascapular nerve, the medial antebrachial cutaneous nerve, the lateral antebrachial cutaneous nerve, the palmar cutaneous branch of the median nerve, the long thoracic nerve, the intercostobrachial nerve, the posterior cutaneous nerve, the infrapatellar branch of the saphenous nerve, the medial calcaneal nerve, and the deep peroneal nerve at the ankle. Following our recommendations, these nerves can be swiftly located and tracked along their course to the site of the pathology.

Frequency and risk factors for major complications after stereotactic radiofrequency ablation of liver tumors in 1235 ablation sessions: a 15-year experience.

OBJECTIVES: To assess the frequency of major complications after multi-probe stereotactic radiofrequency ablation (SRFA) in a large cohort of patients over 15 years and to elucidate risk factors for adverse events. MATERIALS AND METHODS: A retrospective study was carried out between July 2003 and December 2018. Seven hundred ninety-three consecutive patients (median 65.0 years (0.3-88), 241 women and 552 men, were treated in 1235 SRFA sessions for 2475 primary and metastatic liver tumors with a median tumor size of 3.0 cm (0.5-18 cm). The frequency of major complications was evaluated according to SIR guidelines and putative predictors of adverse events analyzed using simple and multivariable logistic regression. RESULTS: Thirty-day mortality after SRFA was 0.5% (6/1235) with an overall major complication rate of 7.4% (91/1235). The major complication rate decreased from 11.5% (36/314) (before January 2011) to 6.0% (55/921) (p = 0.001). 50.5% (46/91) of major complications were successfully treated in the same anesthetic session by angiographic coiling for hemorrhage and chest tube insertion for pneumothorax. History of bile duct surgery/intervention, number of coaxial needles, and location of tumors in segment IVa or VIII were independent prognostic factors for major complications following multivariable logistic regression analysis. Simple logistic regression revealed the number of tumors, tumor size, location close to the diaphragm, tumor conglomerate, and segment VII as other significant predictors. CONCLUSION: SRFA of liver tumors is safe and can extend the treatment spectrum of conventional RFA. Adaptations over time combined with increasing experience resulted in a significant decrease in complications. KEY POINTS: • In 1235 ablation sessions in 793 patients over 15 years, we found a mortality rate of 0.5% (6/1235) and an overall major complication rate of 7.4%, which fell from 11.5 (36/314) to 6.0% (55/921, p = 0.001) after January 2011, likely due to procedural adaptations. • History of bile duct surgery/intervention (p = 0.013, OR = 3.290), number of coaxial needles (p = 0.026, OR = 1.052), and location of tumors in segment IVa (p = 0.016, OR = 1.989) or VIII (p = 0.038, OR = 1.635) were found to be independent prognostic factors. • Simple logistic regression revealed that number of tumors, tumor size, location close to the diaphragm, tumor conglomerates, and segment VII were other significant predictors of major complications.

Role of high-resolution ultrasound in detection and monitoring of peripheral nerve tumor burden in neurofibromatosis in children.

PURPOSE: Peripheral nerve sheath tumors are hallmark findings in neurofibromatosis types 1 and 2. With increasing size, they typically lead to neurological symptoms, and NF1 patients have a lifetime risk of 8-13% for developing malignant peripheral nerve sheath tumors. Medical imaging is therefore highly needed for early detection and exact localization of symptomatic or potentially malignant tumors. This review will give an overview of the ultrasound characteristics of peripheral nerve sheath tumors and findings in patients with neurofibromatosis types 1 and 2. METHODS: A systematic search of electronic databases, reference lists, and unpublished literature was conducted including the keywords "schwannoma," "neurofibroma," "neurofibromatosis," "benign and malignant peripheral nerve sheath tumor." RESULTS: The high-resolution allows a clear analysis of tumor echotexture, definition of margins, and the relation to the parent nerve. The use of color duplex/Doppler and contrast agent adds valuable information for the differentiation of benign and malignant tumors. CONCLUSION: High-resolution ultrasound is a well-established, non-invasive, and easily repeatable first-line tool in diagnostic procedures of soft tissue tumors.

Supernumerary kidneys: a clinical and radiological analysis of nine cases.

BACKGROUND: A supernumerary kidney (SK) is an additional kidney with its own capsule and blood supply that is not fused with the ipsilateral kidney (IK). Because individual case reports indicate a high morbidity rate, the aim of this retrospective study was a detailed analysis of this rare anatomical variant. METHODS: Our systematic imaging-based search for SKs, conducted in the period from 2000 and to 2017, yielded 9 cases in total (5 men, 4 women; mean age: 51.8 ± 22.8 years). RESULTS: The SKs were observed on the right in six and on the left side in three cases. In six subjects (66%) they were located caudal and in three cases (33%) cranial to the ipsilateral kidney. Calculi were found in three (33%) of the renal collecting systems. Five (56%) of the SKs had hydronephrosis grade IV and one SK had recurrent pyelonephritis (11%). Two of the ureters opened into the ipsilateral seminal vesicle (22%). Two (22%) SKs were functional but atrophic. Clinically relevant findings were made in 33% of the IKs: atrophy (n = 2), calculi (n = 1), and reflux with recurrent pyelonephritis (n = 1); another 33% had anatomical anomalies without functional impairment. The correct diagnosis of a SK is possible using CT imaging in all subjects. The prevalence of SK based on CT imaging can be estimated to be 1:26750. CONCLUSIONS: CT is the method of choice for visualizing SKs. The correct diagnosis is crucial in preventing dispensable surgical procedures and for providing optimal patient treatment and outcome.

Soft-Tissue Tumor Contrast Enhancement Patterns: Diagnostic Value and Comparison Between Ultrasound and MRI.

OBJECTIVE: The purpose of this study was to assess and compare contrast-enhanced ultrasound and MRI patterns in the diagnosis of soft-tissue masses. MATERIALS AND METHODS: Two hundred fifty-five consecutively registered patients with histologically confirmed soft-tissue masses were included in this retrospective study. The diagnostic properties of four predefined contrast enhancement (CE) patterns were assessed, and logistic regression analysis was performed to determine the correlation between diagnosis and CE pattern, lesion size, and patient age and sex. The influence of lesion size on the occurrence of inhomogeneous CE patterns in malignancies was also determined. RESULTS: Homogeneous CE patterns were highly specific for benignity, and inhomogeneous CE was moderately specific for malignancy in both ultrasound and MRI. A combination of homogeneous and inhomogeneous CE patterns led to 88.3% and 88.7% sensitivity, 66.7% and 59.7% specificity, 73.4% and 68.2% correct classification, 54.6% and 47.8% positive predictive value, 92.6% and 92.7% negative predictive value, 2.65 and 2.20 positive likelihood ratio, and 0.18 and 0.19 negative likelihood ratio for contrast-enhanced ultrasound and contrast-enhanced MRI. Cases with homogeneous CE in either ultrasound or MRI also were predominantly benign. The occurrence of inhomogeneous CE in malignant lesions increased with size. CONCLUSION: CE patterns in ultrasound and MRI offer additional information about the differentiation of an unknown soft-tissue mass. The results of this study showed that homogeneous or absent CE was specific for benign differentiation and that heterogeneous CE was linked to malignancy. The routine analysis of CE patterns should increase diagnostic reliability in unclear soft-tissue masses.

Measures to Prevent Air Embolism in Transthoracic Biopsy of the Lung.

OBJECTIVE: Systemic air embolism (AE) is a rare but feared complication of transthoracic biopsy with potentially fatal consequences. The aim of the study was to assess the effect of patient positioning during transthoracic biopsy on preventing systemic AE. MATERIALS AND METHODS: We compared a historical control group of 610 patients (group 1) who underwent transthoracic biopsy before the implementation of measures to prevent systemic AE during transthoracic biopsy and a group of 1268 patients (group 2) who underwent biopsy after the measures were implemented. The patients in group 2 were placed in the ipsilateral-dependent position so that the lesion being biopsied was located below the level of the left atrium. RESULTS: The rate of systemic AE was reduced from 3.77% to 0.16% (odds ratio [OR], 0.040; 95% CI, 0.010-0.177; p < 0.001). Logistic regression analyses identified needle penetration depth, prone position of the patient during biopsy, location above the level of the left atrium, needle path through ventilated lung, and intubation anesthesia as independent risk factors for systemic AE (p < 0.05). Propensity score-matched analyses identified the number of biopsy samples obtained as an additional risk factor (p = 0.003). The rate of pneumothorax was reduced from 15.41% in group 1 to 5.99% in group 2 (OR, 0.374; 95% CI, 0.307-0.546; p < 0.001). CONCLUSION: Performing transthoracic biopsy with the patient in an ipsilateral-dependent position so that the lesion is located below the level of the left atrium is an effective measure for preventing systemic AE. Needle path through ventilated lung and intubation anesthesia should be avoided whenever possible.

Prognostic factors in endovascular treated pelvic haemorrhage after blunt trauma.

BACKGROUND: Angioembolization is the method of choice for treating haemorrhage after blunt pelvic trauma. The aim of this study was to determine technical factors related to endovascular procedures which might be related to patient outcome. METHODS: This retrospective study included 112 consecutive patients (40 women and 72 men; mean age 57.2 ± 20.0). RESULTS: There were age peaks at 43 and at 77 years. Patients over 65 years had mainly "low-energy" trauma; younger patients were more likely to have polytraumas. Younger patients were more severely injured and had more surgical interventions, larger haematoma volumes, lower Hb levels and required more transfusions than older patients. Women were older than men, had fewer surgeries and waited longer for an angiography (p < 0.05 each). Logistic regression analyses identified the injury severity score (ISS) as relevant for survival before age, haematoma volume and Hb. Propensity score analyses showed that in addition to the need for transfusions, haemoglobin, and haematoma volume, the length of the coils and the number of microcoils used were relevant (p < 0.05 each). The location of haemorrhage in peripheral parietal arteries (superior and inferior gluteal artery) was an influencing factor for re-angiographies, which were associated with considerably longer hospital stays of more than 40 days. Fewer particles had generally been used in these patients. CONCLUSIONS: The use of too few coils and not using microparticles in angioembolization for pelvic haemorrhage are major influencing factors for the mortality or re-angiography rate. Special attention should be given to thorough peripheral embolization with microcoils, in particular for haemorrhage from the parietal branches of the internal iliac artery.

A case of crossed-doubled patellar tendon: an atavistic variant, simple mutation or pathologic finding?

Anatomical variants can be found throughout the whole body. Especially in the knee region, some variability has been reported concerning the osseous, tendinous, and muscular system. Beside a few cases of patellar tendon aplasia, no anatomical variations of this tendon are known. We present a rare case of a doubled patellar tendon as an anatomical variant, which to our knowledge, has not been described previously.

Does size reliably predict malignancy in soft tissue tumours?

PURPOSE: In this retrospective study we examined whether size is a viable marker of tumour malignancy in soft tissue masses (STM) and if the ratio of width and length (RALD) of an STM reflects tumour biology more accurately. METHODS: Measurements of maximal lesion size and perpendicular diameter were performed in available MRI and ultrasonography studies of 212 patients (mean age 54.4 ± 17.2 years, male:female 1:1.12) with a histologically verified diagnosis. RESULTS: Overall, 28.2 % of lesions were malignant, 11.1 % intermediate, and 58.8 % benign. Size alone was a weak predictor of malignancy in STMs (sensitivity 68.8 %, specificity 50.3 %, positive predictive value [PPV] 44.0 %, negative predictive value [NPV] 80.4 %). RALD showed better discriminatory power with greater separation between benign and malignant entities and higher values for sensitivity (83.6 %), specificity (53.6 %), and NPV (89.0 %). A weighted combination of size, age and RALD improved diagnostic power, demonstrating higher values for sensitivity (77.0 %), specificity (80.1 %), PPV (61.0 %), and NPV (89.6 %). CONCLUSIONS: Size should not be used alone to estimate an STM's malignancy. RALD better reflects a lesion's growth pattern and a combination of age, size, and RALD helps to discriminate more accurately between benign, intermediate, and malignant entities. These findings should help to estimate easily whether a newly found STM is benign or malignant prior to further workup. KEY POINTS: •Size does not reliably differentiate between benign, intermediate, and malignant tumours •The R ALD (ratio of lateral to axial diameter) improves diagnostic confidence •When combined with age and size, STM differentiation was further enhanced •These measurements can aid in earlier detection of sarcomas.

Pathological fracture of the patella due to an atypical located aneurysmal bone cyst: verification by means of ultrasound-guided biopsy.

INTRODUCTION: We report on a rare case of an atypical located aneurysmal bone cyst (ABC) in the patella presenting with pathological fracture after trauma. MATERIALS AND METHODS: Using all available diagnostic modalities and by means of ultrasound-guided core-needle biopsy an unclear and suspected pathological fractured cystic bone lesion in the patella of a young man could be further clarified. RESULTS: The acquired images suggested the diagnosis of a pathological fractured aneurysmal bone cyst after mild trauma. However, due to the extraordinary location and clinical presentation the diagnosis was secured by means of ultrasound-guided biopsy through a small cortical gap. CONCLUSION: As shown in this rare case of an atypical aneurysmal bone cyst of the patella, the quite seldom but sometimes possible ultrasound-guided biopsy of intraosseous lesions can help to achieve the diagnostic clarification and should also be taken into account as a non-standard procedure.

Triple hourglass-like fascicular constriction of the posterior interosseous nerve: a rare cause of PIN syndrome.

Supinator syndrome or posterior interosseous nerve (PIN) syndrome is a compression neuropathy of the deep branch of the radial nerve in the region of the Arcade of Frohse. An extremely rare cause of an acute onset supinator syndrome is the hourglass-like fascicular constriction of the posterior interosseous nerve due to torsion. To our knowledge, only a limited number of cases which describe the sonographic appearance of fascicular torsions are known in the literature. We present a rare case of a supinator syndrome associated with hourglass-like constrictions of the PIN diagnosed by means of sonography.